Department of Physics & Astronomy, University College London, London, UK.
Interface Analysis Centre, H. H. Wills Physics Laboratory, University of Bristol, Bristol, UK.
Nature. 2019 Apr;568(7751):216-220. doi: 10.1038/s41586-019-1074-x. Epub 2019 Apr 10.
Phosphorene is a mono-elemental, two-dimensional (2D) substance with outstanding, highly directional properties and a bandgap that depends on the number of layers of the material. Nanoribbons, meanwhile, combine the flexibility and unidirectional properties of one-dimensional nanomaterials, the high surface area of 2D nanomaterials and the electron-confinement and edge effects of both. The structures of nanoribbons can thus lead to exceptional control over electronic band structure, the emergence of novel phenomena and unique architectures for applications. Phosphorene's intrinsically anisotropic structure has motivated numerous theoretical calculations of phosphorene nanoribbons (PNRs), predicting extraordinary properties. So far, however, discrete PNRs have not been produced. Here we present a method for creating quantities of high-quality, individual PNRs by ionic scissoring of macroscopic black phosphorus crystals. This top-down process results in stable liquid dispersions of PNRs with typical widths of 4-50 nm, predominantly single-layer thickness, measured lengths of up to 75 μm and aspect ratios of up to 1,000. The nanoribbons are atomically flat single crystals, aligned exclusively in the zigzag crystallographic orientation. The ribbons have remarkably uniform widths along their entire lengths, and are extremely flexible. These properties-together with the ease of downstream manipulation via liquid-phase methods-should enable the search for predicted exotic states, and an array of applications in which PNRs have been predicted to offer transformative advantages. These applications range from thermoelectric devices to high-capacity fast-charging batteries and integrated high-speed electronic circuits.
磷烯是一种单元素、二维（2D）物质，具有出色的、高度各向异性的性质和依赖于材料层数的带隙。与此同时，纳米带结合了一维纳米材料的柔韧性和各向异性、二维纳米材料的高表面积以及两者的电子限制和边缘效应。因此，纳米带的结构可以对电子能带结构进行非凡的控制，产生新的现象和独特的应用架构。磷烯的各向异性结构激发了大量关于磷烯纳米带（PNRs）的理论计算，预测了其非凡的性质。然而，迄今为止，离散的 PNR 尚未被制备出来。在这里，我们提出了一种通过宏观黑磷晶体的离子剪裁来制备大量高质量、独立的 PNR 的方法。这种自上而下的过程产生了稳定的 PNR 液体分散体，其典型宽度为 4-50nm，主要为单层厚度，最长可达 75μm，纵横比高达 1000。这些纳米带是原子级平整的单晶，仅以锯齿状的晶向排列。这些带具有非常均匀的宽度，沿着整个长度方向，并且非常柔韧。这些特性——加上通过液相方法进行下游操作的便利性——应该能够寻找预测的奇异状态，并在一系列应用中，PNRs 被预测具有变革性的优势。这些应用范围从热电设备到高容量快速充电电池和集成高速电子电路。
